A HISTORY OF SCIENCE 



he did, perhaps the most Socratic figure of the century. 

 When, in 1882, he died, friend and foe alike conceded 

 that one of the greatest sons of men had rested from 

 his labors, and all the world felt it fitting that the re- 

 mains of Charles Darwin should be entombed in West- 

 minster Abbey close beside the honored grave of Isaac 

 Newton. Nor were there many who would dispute 

 the justice of Huxley's estimate of his accomplish- 

 ment: "He found a great truth trodden under foot. 

 Reviled by bigots, and ridiculed by all the world, he 

 lived long enough to see it, chiefly by his own efforts, 

 irrefragably established in science, inseparably incor- 

 porated with the common thoughts of men, and only 

 hated and feared by those who would revile but dare 

 not." 



THE ORIGIN OF THE FITTEST 



Wide as are the implications of the great truth which 

 Darwin and his co-workers established, however, it 

 leaves quite untouched the problem of the origin of 

 those " favored variations" upon which it operates. 

 That such variations are due to fixed and determinate 

 causes no one understood better than Darwin ; but in 

 his original exposition of his doctrine he made no as- 

 sumption as to what these causes are. He accepted 

 the observed fact of variation as constantly witnessed, 

 for example, in the differences between parents and 

 offspring and went ahead from this assumption. 



But as soon as the validity of the principle of natural 

 selection came to be acknowledged speculators began 

 to search for the explanation of those variations which, 

 for purposes of argument, had been provisionally called 

 "spontaneous." Herbert Spencer had all along dwelt 



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